From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Photograph of a failed inlet valve spring after a 50-hour endurance test.
| Identifier | ExFiles\Box 123\5\ scan0333 | |
| Date | 24th February 1939 guessed | |
| BENTLEY 60: No.1 UNIT. E.46854 Inlet Valve Spring, after 50 hrs. Endurance Test. | ||